The sound from a mosquito is produced when it vibrates its wings at the average rate of 500 vibrations per second. The time period of the vibration is ____ s.
A source of wave produces 20 crests and 20 troughs in 0.2 s. The distance between a crest and the next trough is 50 cm. Find the wavelength, frequency and time period of the wave.
Cut or take out crops are used in harvesting ground-level or near to it A cereal crop typically matures in three to four months.
The escape velocity of a body projected vertically upwards from the surface of Earth is 11.2 km/s. If the body is projected in a direction making an angle 450 with the vertical, the escape velocity will be
